Present climate and biological change - Climate Change: Biological and Human Aspects - page 218

temperature at the time of Norse occupation was some 2-4 ◦ C higher than at the end
of the 20th century. In reality, the coastlands of the pleasantly named Greenland were
not that much different from Iceland at the time and, if anything, worse, but it was felt
that a country with a nice-sounding name would be more likely to attract new settlers.
Archaeological evidence has revealed that Icelandic Vikings had large farmsteads
with cattle, pigs, sheep and goats, and there were ample pastures to sustain these
as well as crops such as barley. However, the growing season in Greenland, even in
the MCA, was very short. Frost typically occurred in August and the fjords froze
in October. Nonetheless, by the 1300s more than 3000 colonists lived on 300 farms
scattered along the west coast of Greenland.
This was all to change with the Little Ice Age. Indeed, well into this cool period, in
1492, the Pope complained that no bishop had been able to visit Greenland for 80 years
on account of the sea ice. In fact, by that time his Greenland congregation was in all
likelihood either already dead or had migrated. Hermann (1954) notes that during the
mid 1300s many Greenlanders had moved on to Markland (today's Newfoundland)
in search of a more benign home. Formal communication between Greenland and
Europe had ceased in 1410 and was not re-established until the 1720s. Europeans
did not recolonise that area until the 1800s. Meanwhile, Icelandic grain production
was given up in the 14th century and in 1695 sea ice completely surrounded Iceland
except for one port. This ties in with the aforementioned reports that in Western
Europe in the 1690s crop failures were common. It was the coldest decade of the 17th
century.
As noted at the start of this chapter, systemised meteorological recording began in
the 18th century and has continued to the present day. Not surprisingly, the coldest
year on this record occurred during the Little Ice Age. It was 1816 and followed the
eruption in 1815 of Mount Tambora in Indonesia. The eruption distributed aerosols
into the stratosphere which cooled the Little Ice Age climate further. In addition,
1816 saw the latest grape harvests ever recorded: November. Meanwhile, in eastern
Canada and New England three cold waves in June, July and the end of August (with
frosts) devastated harvests and damaged crops as far south as Boston, MA, USA.
Harvests were down across the northern hemisphere and there is even a record of
famine in Bengal that triggered an outbreak of cholera. The 1816 cholera epidemic
even became global (the world's first pandemic of the disease), reaching Western
Europe and North America by 1832.
In terms of human mortality, correlation of the CET record between 1665 and 1834
with mortality reveals that mortality increased in both cold winters and hot summers.
Quantitatively, warming of 1 ◦ C in winter and cooling of 1 ◦ C in summer reduced
seasonal mortality by 2 and 4%, respectively. The combination of such mild winters
and cool summers was to raise life expectancy by about 2 years. We will revisit this
when discussing health impacts of future climate change in Chapter 7, and it will be
important to remember that the age profile of early 21st-century developed nations
is far different to their 18th-century counterparts, with a higher proportion of elderly
people. Nonetheless, climate-related health effects, albeit to an increasingly different
degree, were still relevant through the 19th and 20th centuries. As recently as 1940,
UK mortality from bronchitis and pneumonia was, at more than 850 000, double the
remainder of the decade's average, and correlated with that year's cold winter. The